Real Presence Group 500 calls to Skype for Business does not connect

Hello,

I'm currently using the Real Presence Group 500 version 6.11. I also have the Real Presence Touch and the Skype for Business Online registers without any issues.

Each time I try to place a call using the RP Group to Skype for Business Ccontact, the calls does not connect, rather it says failed.

I'm able to use my normal Skype for Business client with the same credentials to Login and make Video calls but I can't initiate calls or join meetings using the RP group.

I've attached the CDR and Logs.

Kindly assist .

Thank you